I have a bad chicken poop problem. Can chickens be toilet trained?

Hi, I know it's a really silly question and I don't think chickens can be trained, but I do have a bad chicken poop problem.
During the day, I let my three 17 week old chickens out of their coop to free range my huge backyard. They have no interest free ranging at all and are more interested in sitting or knock on my backdoor and leave behind piles of poop. Now the knocking drives me nuts,but the poop is starting to make its way into the house, courtesy of my family of 4 stomping through.
I can not put a fence and gate up, because my little dogs kennel is right next to the backdoor and there is no where else sheltered enough to put it. She needs to be able to go down the stairs and do her business on the lawn. If I lock her in and the chickens out I will just end up with more poop, but just a different variety.
I've shoe them away every time and have even hosed them, but they do not get the message.
Has any one out there BYC land got any idea's I may try to get them to understand that the backdoor area is forbidden ground and off limits to them?

 

appps it's a great idea, but my little darling dog is very old and has arthritis. She is also scared of doggie flaps, as I tried with her with one in the past on her kennel to keep her warm in winter. I had to use a little door on hinges, she just pushes the door open and then walks out. I really wish I knew what deters chickens.

 

Has anyone tried those croaking frog statues that have sensors and if so do they work or do the chickens just work it out?